Warehouse-door.



No. 766,762. PATENTED AUG. 2, 1904. J. ERWOOD.

WAREHOUSE DOOR.

APPLIUATIQN P-ILED APR. 27, 1903.

H0 MODEL.

lllilil "ii ....||1!mum VENTOR 9 WITNESSES 1'4 W V ATTORNEY 8 NITED STATES Patented August 2, 1904.

JOHN ERXVOOD, OF CHICAGO, ILLINOIS.

WAREHOUSE-DOOR SPECIFICATION forming part of Letters Patent No. 766,762, dated August 2, 1904.

Application filed April 27, 1903. Serial No. 154,378. (No model.)

To a, whmn it TH/H/Z/ concern.-

Be it known that I, J OIIN ERWOOD, acitizen of the United States, residing at No. 1604: \Ncst Adams street, in the city of Chicago, in the county of Cook and State of Illinois, have invented new and useful Improvements in \Varehouse- Doors, of which the following is a specification, reference being had to the accompanying drawings, forming a part thereof.

T his invention is an improved folding warehouse-door, designed to simplify the construction and reduce the amount of counterweight required.

It consists in the features of construction which are set out in the claims.

In the drawings, Figure 1 is a front elevation of a warehouse-door and operating devices embodying my invention, the door being shown in closed position. Fig. 2 is a vertical section at the line 2 2 on Fig. 1, showing the door in full line at closed position and in dotted line at open position. Fig. 3 is a detail elevation of the devices by which the door is hung at the top, seen from the opposite side from which they appear in Fig. 2. Fig. at is a section similar to Fig. 3, showing a modified construction. Fig. 5 is a View similar to Fig. 4, showing the door at elevated or open position.

My improved door comprises an upper section 1 and a lower section 2, locked together at a horizontal line approximately midway in the height of the door. To the upper doorsection at the upper side at each end there is secured a gear-segment 3, and on the wall 4t at each end of the door-opening and above the latter there is mounted a rack 5, with which the gear-segment 3 engages. This rack 5 is formed on a bracket which has a flange 6 projecting out from the wall and provided with a slot 7, extending vertically parallel with the rack 5, and into this slot a guide stud and roll 8, which projects at the center of the gearsegment, takes for guidance of the latter and for retaining the segment meshed with the rack. Considering now the upper section of the door only, it will be understood that it might be suspended by means of the engagement of the segments with the racks and the guides 8 with the slots 7 and that if being thus suspended the lower edge should be swung outward from the wall to uncover the dooropening the result would be the rolling of the gear-segments up along the racks to which they are engaged, while the guides 8 would travel up in their respective guide-slots, and that the door-section would thereby be caused not only to swing outward away from the wall, but also to travel upward along the wall at its upper end, and that by the time it reached a horizontal position extending outward from the wall it would be at a position higher than its upper edge occupied when the door-section hung vertically by an amount equal to onefourth the circumference of a circle having the radius of the gear-segment less such radius, since said gear-segment will have rocked through ninety degrees in said swinging movement. The same movement being performed while the lower section of the door is hinged to the lower edge of the upper section will have carried the upper edge of said lower section upward and outward in the same path taken by the lower edge of the upper section, and I provide the lower edge of the lower section with guide-studs 9 9, taking into suitable vertical guide-channels 10 10, mounted on the wall at the opposite sides of the door-opening, and since the upper edge of the upper section when said section reaches the hori- Zontal position shown in Fig. 3 will stand outward from the plane at which the door hung suspended by the amount of the radius of the gear-segments I make the lower section of the door wider than the upper by this amount, so that the guide-studs at its lower edge traveling in the guide-channels need not leave the vertical plane in which the door hangs when closed.

To counter-poise the door, lifting-cables are attached to the lower section at the lower cornersas, for example, on the guide-studs 9 9and extending up along the edges of the door in the guide-channels are carried over pulleys 12 12 at the top and thence over any other convenient guidepulleys to a point where provision will be made for the weights 13 to descend as the door is lifted.

It will be seen upon inspection that the entire weight of the door when it hangs closed may be sustained by the racks with which the gear-segments are engaged, and this being the case the weight necessary to sustain the door at any open or partly-open position will be only the amount which will be necessary to sustain the upper section in position with its lower edge swung outward from the wall added to the amount necessary to sustain the lower door-section similarly deflected from vertical position, as it would hang suspended from the lower edge of the upper section and deflected thence back inward to the vertical plane of the door at closed position. When the door is fully elevated. this amount would be one-half the weight of the two sections; but at any position lower than this it would be less than that amount, being least at the least open position of the door. Since at the most elevated position the weight of the door operates with horizontal endwise thrust on the lower element, thrusting the-studs 9 horizontally against the sides of the guide-channels, and with an outward pull on the guide-studs 8 against the sides of the slots 7 it will be evident that less than the theoretical counterweight will hold the door elevated, because the friction will so largely resist its descent, and since the weight required to start the door up from its closed position is so much less than that required to uphold it when fully elevated, as much less weight than the theoretical requirement for counterpoising the door when fully elevated as may be found adequate to sustain it in view of the assistance of the friction will be adequate to start the door up with considerable velocity when it is released, and the momentum acquired in the lower part of its course will be adequate to cause it to reach the fully-elevated position, at which the same weight, assisted by the friction, will sustain it. I do not limit myself, however, to employing a uniform counterweight; but any of the familiar means for obtaining a graduated action of the counterweight corresponding to the increasing weight as the door rises may be employed. When, however, the uniform weight is employed, as shown in the drawings, catches should be provided, securing the door at closed position. These may consist of horizontally-shot bolts 23 23 at the lower edge, connected by links 14L to a rotary handle 14E at the middle of the width of the door, by which they may both be withdrawn simultaneously when the door is to be elevated.

In Fig. A I have shown a modification which consists in connecting the gear-segments to the door, not rigidly, but so that they have a limited range of pivotal action about the center of the segment, a spring being provided operating between the segments and the bracket by which it is pivoted on the door, with a tendency to rock the segments downward relatively to the bracket. and thereby when the segments are engaged with ments up to the limit permitted by the slot.

The operation of this structure is that as the door is lifted and folded the action of the spring tends to roll the segment farther up on the rack than it would be rolled by the. swinging of the upper element of the door if it were rigid, and thereby the door is carried higher than in the other form.

l. A warehouse-door comprising an element having gear-segments at the top; vertical racks mounted on the wall with which said gear-segments mesh; means for guiding the centers of the segments vertically parallel with the racks respectively, and means for actuating said door element to swing it from vertical to horizontal position.

2. A warehouse-door comprising an upper and lower element hinged together; gear-segments at the top of the upper element; vertical racks on the wall with which such segments mesh; means for guiding the center of the segments vertically parallel with the racks respectively, and means guiding the lower edge of the lower element vertically, and for upholding said element at the bottom.

3. A warehouse-door comprising, in' combination with two elements hinged together at a horizontal line, gear-segments connected to the upper element at the top; vertical racks with which such segments mesh fixed on the wall; guideways rigid and parallel with said racks respectively, and guides projecting at the centers of the segments respectively into said guideways; means for guiding the bottom of the lower element vertically, and means for upholding said lower element at the bottom.

4:. A warehouse-door comprising an upper and lower elementhinged together; gear-segments at the top of the upper element; vertical racks on the wall with which the segments mesh; means for guiding the centers of the segments vertically parallel with the racks; means for guiding the lower corners of the lower element vertically, and cables connected to said lower corners and extending up along the edges of the door; pulleys above the level of the racks vover which the cables pass, and counterbalancing-weights on said cables beyond the pulleys.

5. A warehouse-door comprising an upper and lower element hinged together; gear-segments pivotally mounted at their centers at the upper end of the upper element; vertical racks mounted on the wall with which said segments engage; means for guiding the centers of said segments vertically parallel with the racks; springs reacting between the segments and the door to rock the segments downward, whereby said springs tend to lift the door; means for lifting the lower end of the lower element and for guiding the same vertically.

6. A warehouse-door comprising an element having gear-segments mounted upon it; vertical racks mounted in fixed position with respect to the door-opening with which the gearscgments mesh; means for guiding the segments to retain them in mesh with the racks as the door swings between vertical and hori- Zontal position, and means for actuating the door to swing it thus.

7. A warehouse-door comprising an upper and lower element hinged together; gear-segments secured to the upper element; racks mounted in fixed position with respect to the door-opening with which said gear-segments mesh; means for guiding the segments to retain them in mesh with the racks respectively as the upper element of the door swings between vertical and horizontal position, and means for guiding the lower element vertically at a point below the hinges, and for upholding said element at such point.

8. A warehouse-door comprising an element having gear-segments pivotally mounted on it; vertical racks mounted in fixed position with respect to the door-opening with which said segments engage; means for guiding the segments to retain them in mesh with the rack respectively; springs reacting between the segments and the door to rock the segments downward about their respective pivots,

whereby the springs tend to lift the door, and means for actuating said door element to swing it from vertical toward horizontal position.

9. A warehouse-door comprising an upper and lower element hinged together; gear-segments pivotally mounted on the upper element; racks mounted in fixed position with respect to the door-opening, with which said segments respectively engage; means for guiding the segments to retain them in mesh with the racks respectively while the upper element of the door swings between vertical and 

